WO2025207958A9 - Method and system for converting mixed alcohol composition to hydrocarbon fuels and method of making the same - Google Patents

Abstract

The present disclosure is directed to a method and system for making a C₃₊ mixed alcohol composition that can be used to prepare hydrocarbon fuels. The method comprises combined front-end and back-end processes for preparing the C₃₊ mixed alcohol composition from a starting feedstock (front-end) and converting the composition to hydrocarbon fuels (back-end). Additional co-products also are prepared during the process that can be isolated and used as commodity chemicals in other processes and/or added back to the method to increase yields.

Description

METHOD AND SYSTEM FOR CONVERTING MIXED ALCOHOL COMPOSITION TO HYDROCARBON FUELS AND METHOD OF MAKING THE SAME

CROSS REFERENCE TO RELATED APPLICATION

[0001 ] This application claims the benefit of, and priority to, the earlier filing date of U.S. Provisional Application No. 63/571 ,612 filed on March 29, 2024, the entirety of which is incorporated herein by reference.

ACKNOWLEDGMENT OF GOVERNMENT SUPPORT

[0002] This invention was made with government support under DE-AC0576RL01830 awarded by the U.S. Department of Energy. The government has certain rights in the invention.

FIELD

[0003] The present disclosure is directed to embodiments of a method and a system (including reagents used therein) used to produce hydrocarbon fuels using a mixed Cs₊ alcohol feed.

BACKGROUND

[0004] Current sustainable aviation fuel (SAF) production, both current and projected, falls well short of the targets needed to meet the US Grand SAF challenge goals and to lower the highly negative carbon emission impacts of rapidly growing commercial aviation fuel demands, estimated to reach 35 billion gal/yr by 2050. Yet very few renewable resources can currently be leveraged to sufficiently meet even a fraction of this expected demand. One of the best candidates currently available is renewable ethanol, which can be generated in large volumes from a variety of feedstocks across the globe in excess of 30 billion gallons per year in a distributed manner. Not only is the current bioethanol production and distribution a highly mature and optimized industry, ethanol can also be derived from a wide variety of other sources, including cellulosic biomass, shale gas, municipal solid waste (MSW), biogas, and flue gas. Many of these sources may potentially provide ethanol feedstock at an even lower energy intensity and greenhouse gas (GHG) footprint compared to corn ethanol (e.g., MSW, flue gas). These characteristics make ethanol an ideal platform intermediate for the development of low carbon renewable fuels capable of displacing petroleum-based products at significant market volumes. Given its suitability as a feedstock, one hurdle is developing highly efficient and low carbon intensity conversion technologies. Also, given the extreme cost sensitivity of SAF end consumers, promising technologies must be able to retain high carbon and energy efficiency across the process to minimize production costs while limiting the overall carbon intensity to take advantage of potential incentives. There exists a need in the art for a new method that can provide access to hydrocarbon fuels using different available feedstocks (e.g., ethanol and other oxygenates) using conditions and reagents that avoid fallbacks associated with conventional methods.

SUMMARY

[0005] Disclosed herein, along with additional aspects as described in the present disclosure, is a method for forming a hydrocarbon fuel product, comprising: forming a C3+ mixed alcohol composition from a feedstock; exposing the C3+ mixed alcohol composition to an acidic silicoaluminate catalyst in a dehydration zone operated at a pressure ranging from 400 psig to 550 psig and a temperature ranging from 200 °C to 400 °C to provide a Cs+ mixed olefin composition; exposing the Cs₊ mixed olefin composition to a zeolite material in an oligomerization zone operated at a pressure ranging from 400 psig to 550 psig and a temperature ranging from 200 °C to 350 °C to provide a Cs+ mixed olefin composition; and exposing the Cs+ mixed olefin composition to a metal-modified silicoaluminate catalyst in the presence of hydrogen in a hydrogenation zone to provide the hydrocarbon fuel product.

[0006] Also disclosed is a method for forming a hydrocarbon fuel product, comprising: exposing a C24 alcohol to a mixed oxide catalyst in a condensation zone to produce a C3+ mixed ketone composition, wherein the mixed oxide catalyst comprises a metal promoter selected from Au, Cu, Ag, Pt, Ru, Rh, Pd, Os, Ir, or any combination thereof; exposing the C3+ mixed ketone composition to a hydrogenation catalyst to provide a C3+ mixed alcohol composition, wherein the hydrogenation catalyst is present in the condensation zone or is present in a separate hydrogenation zone; exposing the Cs₊ mixed alcohol composition to a dehydration catalyst in a dehydration zone operated at a pressure ranging from 0 psig to 1000 psig and a temperature ranging from 50 °C to 500 °C to provide a C3+ mixed olefin composition; exposing the Cs+ mixed olefin composition to an oligomerization catalyst in an oligomerization zone operated at a pressure ranging from 0 psig to 1000 psig and a temperature ranging from 50 °C to 400 °C to provide a Cs+ mixed olefin composition; and exposing the Cs+ mixed olefin composition to a hydrogenation catalyst in the presence of hydrogen in a hydrogenation zone to provide the hydrocarbon fuel product.

[0007] Also disclosed herein is a method for forming a hydrocarbon fuel product, comprising: exposing a C24 alcohol to a heterogeneous Guerbet catalyst in a condensation zone to produce an oxygenate composition comprising 1 -butanol, wherein the heterogeneous Guerbet catalyst comprises a metal dispersed on a mixed oxide support; exposing the oxygenate composition to dehydration catalyst in a dehydration zone operated at a pressure ranging from 0 psig to 1000 psig and a temperature ranging from 50 °C to 500 °C to provide a C3+ mixed olefin composition; exposing the C3+ mixed olefin composition to an oligomerization catalyst in an oligomerization zone operated at a pressure ranging from 0 psig to 1000 psig and a temperature ranging from 50 °C to 400 °C to provide a Cs+ mixed olefin composition; and exposing the Cs+ mixed olefin composition to a hydrogenation catalyst in the presence of hydrogen in a hydrogenation zone to provide the hydrocarbon fuel product.

[0008] The foregoing and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIGS. 1A and 1 B are schematic illustrations of the steps and products formed under different front-end processes that can be used in combination with a back-end process according to aspects of the present disclosure, wherein FIG. 1 A shows a ketonization-hydrogenation combination process and FIG. 1 B shows a Guerbet-polishing combination process.

[0010] FIG. 2 provides schematic illustrations of steps used in two aspects of the method disclosed herein wherein a ketonization-hydrogenation combination front-end process is combined with a back-end process according to aspects of the disclosure, with the top schematic showing an aspects where ketonization and hydrogenation take place in the same reaction zone and the bottom schematic showing an aspects where ketonization and hydrogenation take place in separate reaction zones.

[0011 ] FIG. 3 is a schematic illustrating an exemplary system set-up and process flow used for combining a ketonization-hydrogenation combination process with back-end process steps according to aspects of the disclosure.

[0012] FIG. 4 is a schematic illustration of steps and exemplary catalysts used in a method according to aspects of the disclosure wherein a ketonization-hydrogenation combination front-end process is combined with a back-end process according to aspects of the disclosure.

[0013] FIG. 5 is a schematic illustration of steps used in a method according to aspects of the disclosure wherein a Guerbet-polishing combination front-end process is combined with a back- end process according to aspects of the disclosure.

[0014] FIG. 6 is reaction scheme summarizing steps and products formed during a Guerbet condensation process.

[0015] FIG. 7 is a graph of duty (MBTU / kMol Carbon) as a function of carbon number, showing the differences between dehydration duty associated with a mixed alcohol composition obtained from Guerbet condensation as compared with ethanol. [0016] FIG. 8 is a graph of conversion (%) as a function of temperature (°C) showing the differences in temperature needed to convert an exemplary alcohol obtained from Guerbet condensation (e.g., 1 -butanol) as compared with ethanol.

[0017] FIG. 9 is a graph showing an estimation of H₂ demand, taking into account in-situ H₂ generated from ketone production as well as the corresponding trade off in CO₂ production, based on using a method according to aspects of the present disclosure wherein a Guerbet-polishing combination process is combined with a back-end process.

[0018] FIG. 10 is a schematic illustration showing how side-products (e.g., H₂ and CO₂) from the hydrogenation process of a back-end process according to the present disclosure can be converted to valuable commodity products, such as methanol and/or methane.

[0019] FIGS. 11 A and 11 B are graphs summarizing results obtained from a ketonization process according to aspects of the present disclosure wherein pressure was varied, with FIG. 11 A showing the alcohol to ketone ratio (%) observed at the different evaluated pressures and FIG.

11 B showing the yield of jet-range products (%) obtained at the different evaluated pressures.

[0020] FIGS. 12A and 12B summarize results for conversion of ethanol to ketones using a ketonization process according to the present disclosure, wherein the conversion is summarized as a function of WHSV (hr¹) (FIG. 12A) and time on stream (hours) (FIG. 12B).

[0021] FIGS. 13A and 13B summarize results for conversion of ketones to a Cs₊ mixed alcohol composition using a front-end hydrogenation process according to the present disclosure, wherein the conversion is summarized as a function of WHSV (hr¹) (FIG. 13A) and time on stream (hours) (FIG. 13B).

[0022] FIGS. 14A-14D summarize results for conversion of a Cs+ mixed alcohol composition to a Cs₊ mixed olefin composition using a dehydration process according to the present disclosure, wherein the conversion is summarized as a function of WHSV (hr¹) (FIG. 14A) and time on stream (hours) (FIG. 14B) and also show comparison of dehydration duty (FIG. 14C) and dehydration temperature (FIG. 14D) for a conventional ethylene-based pathway for producing SAF as compared with a method according to aspects of the disclosure.

[0023] FIGS. 15A and 15B summarize results for conversion of a Cs+ mixed olefin composition to a Cs+ mixed olefin composition using an oligomerization process according to the present disclosure, wherein the conversion is summarized as a function of WHSV (hr¹) (FIG. 15A) and time on stream (hours) (FIG. 15B). [0024] FIG. 16 summarizes yields and types of products obtained from exposing a Cs+ mixed olefin composition to hydrogenation to form a SAF product.

[0025] FIG. 17 is a graph comparing a SAF product made according to aspects of the present disclosure as compared with a conventional jet range product and which shows that the SAF product of the present disclosure meets Tier a & p specifications for jet fuel.

[0026] FIG. 18 is a graph of conversion (%) as a function of time on stream, showing selectivity and yield results for a Guerbet condensation process wherein a starting feedstock is converted to a mixed alcohol composition according to aspects of the present disclosure.

[0027] FIG. 19 is a graph of alcohol carbon yield (%) as a function of time on stream showing results obtained from a polishing step (e.g., hydrogenolysis) used to convert a carbonyl-containing oxygenate compound (ethyl acetate) to an alcohol.

[0028] FIG. 20 shows a gas chromatogram of jet-range alkene products produced from oligomerizing a C3+ mixed alcohol composition obtained from a front-end process using Guerbet condensation and a polishing process.

[0029] FIGS. 21 A and 21 B show results obtained from using CO2 and H₂ made during a method according to the present disclosure to form co-products, such as methanol and/or methane, wherein FIG. 21 A shows methane/methanol production as a function of average ketone carbon number; and FIG. 21 B shows CO₂ carbon yield (%) as a function of average ketone carbon number.

DETAILED DESCRIPTION

Overview of Terms

[0030] The following explanations of terms and abbreviations are provided to better describe the present disclosure and to guide those of ordinary skill in the art in the practice of the present disclosure. As used herein, “comprising” means “including” and the singular forms “a” or “an” or “the” include plural references unless the context clearly dictates otherwise. The term “or” refers to a single element of stated alternative elements or a combination of two or more elements, unless the context clearly indicates otherwise.

[0031] Unless explained otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure, suitable methods and materials are described below. The materials, methods, and examples are illustrative only and not intended to be limiting. Other features of the disclosure are apparent from the following detailed description and the claims.

[0032] The disclosure of numerical ranges should be understood as referring to each discrete point within the range, inclusive of endpoints, unless otherwise noted. Unless otherwise indicated, all numbers expressing quantities of components, molecular weights, percentages, temperatures, times, and so forth, as used in the specification or claims are to be understood as being modified by the term “about.” Accordingly, unless otherwise implicitly or explicitly indicated, or unless the context is properly understood by a person of ordinary skill in the art to have a more definitive construction, the numerical parameters set forth are approximations that may depend on the desired properties sought and/or limits of detection under standard test conditions/methods as known to those of ordinary skill in the art. When directly and explicitly distinguishing aspects of the disclosure from discussed prior art, the disclosed numbers are not approximates unless the word “about” is recited.

[0033] Also, the following description is exemplary in nature and is not intended to limit the scope, applicability, or configuration of the present disclosure. Various changes to the described aspects of the disclosure may be made in the function and arrangement of the elements described herein without departing from the scope of the present disclosure. Further, descriptions and disclosures provided in association with one particular aspect are not limited to that aspect, and may be applied to any aspect disclosed. Further, the terms “coupled” and “associated” generally mean fluidly, electrically, and/or physically (e.g., mechanically or chemically) coupled or linked and does not exclude the presence of intermediate elements between the coupled or associated items absent specific contrary language.

[0034] Although the operations of exemplary aspects of the disclosed method and/or system may be described in a particular, sequential order for convenient presentation, it should be understood that disclosed aspects can encompass an order of operations other than the particular, sequential order disclosed, unless the context dictates otherwise. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Further, descriptions and disclosures provided in association with one particular aspect are not limited to that aspect, and may be applied to any disclosed aspect.

[0035] To facilitate review of the various aspects of the disclosure, the following explanations of specific terms are provided.

[0036] Alcohol: An organic compound comprising at least one hydroxyl group (-OH).

[0037] Aldehyde: R^aC(O)H, wherein R^a is an alkyl group. [0038] Alkyl: A saturated monovalent hydrocarbon having at least one carbon atom to 50 carbon atoms (C1-50), such as one to 25 carbon atoms (C1-25), or one to ten carbon atoms (Ci-w), wherein the saturated monovalent hydrocarbon can be derived from removing one hydrogen atom from one carbon atom of a parent compound (e.g., alkane). In some aspects, an alkyl group can be branched, straight-chain, or cyclic (e.g., cycloalkyl).

[0039] Carbonyl-Containing Compound: An organic compound comprising at least one C=O functional group.

[0040] Carboxylic Acid: R^aC(O)OH, wherein R^a is an alkyl group.

[0041 ] Ester: R^bC(O)OR^a or R^bOC(O)R^a, wherein R^a and R^b independently are an alkyl group.

[0042] Hydrocarbon fuel product: A composition that comprises, as a majority component (such as more than 85 wt% to 99.9 wt% or more of the total weight of the composition), saturated hydrocarbons having at least 8 carbon atoms, such as saturated hydrocarbons having carbon numbers ranging from C8 to C18 (or higher). In particular aspects, the saturated hydrocarbons comprise a majority portion that comprises hydrocarbons having carbon numbers ranging from C8 to C16. In some aspects of the disclosure, the hydrocarbon fuel product is suitable for use as aviation fuel. In some such aspects, the hydrocarbon fuel product typically excludes levels of oxygenates, unsaturated aliphatics, and/or aromatics that would result in the fuel product not being classifiable as an aviation fuel. Solely by way of example, amounts of such components that would decrease thermal stability below acceptable levels in the art typically are excluded. In some aspects, the hydrocarbon fuel product may comprise a mixture of compounds suitable as aviation fuel, biofuel, or mixtures thereof, wherein such fuels can be distilled and separated.

[0043] Ketone: A compound comprising a ketone group R^aC(O)R^b, wherein each R^a and R^b independently is an alkyl group.

[0044] Lower Olefin Portion: A portion of a Ca+ mixed olefin composition that is comprised of lower olefins, such as olefins having carbon numbers from C7 or lower.

[0045] Olefin: An organic compound comprising at least one site of unsaturation. In some aspects, an olefin comprises at least one carbon-carbon double bond.

[0046] Oxygenate: A hydrocarbon-based compound comprising at least one oxygen atom.

Introduction

[0047] The current state-of-the-art ethanol to SAF technologies include processes based around an ethylene intermediate, which is produced via dehydration of ethanol and is subsequently oligomerized in a two-step process, first to 1 -butene and then to jet-range alkenes before a final hydrogenation step to generate SAF. This two-step process is required because, unlike C3+ alkenes, which can be readily converted via standard acid-catalyzed oligomerization, ethylene is highly stable and must be specifically activated on a Ni-based catalyst to properly react.

[0048] One of the major challenges with conventional techniques lies in the high energetic requirements and process complexities of ethanol dehydration, a highly endothermic reaction. Other implementations utilize specialized resin catalysts in combination with complex separation, purification, and recycling steps to achieve ethylene high purity, which can demand up to 70% of the total plant energy costs. This challenge is greatly heightened by the well-documented sensitivity of heterogeneous Ni-based catalysts. Also, common impurities, such as water and oxygenate compounds, easily adsorb onto the Ni active site, causing irreversible poisoning and rapid deactivation. This limitation imposes even greater front-end requirements for separation and purification to generate a sufficiently clean ethylene stream that protects the Ni catalyst. Alternative approaches utilizing homogeneous Ni⁺² catalysis are burdened by the high costs associated with catalyst recovery from solution as well as the catalyst itself.

[0049] The present disclosure is directed to a method for converting a C3+ mixed alcohol composition to hydrocarbon fuel products, such as SAF products, using a combination of processing steps that facilitate using similar pressures across reactors and steps of the method, exhibit high water tolerance, produce H₂ that can be used in the process to thereby omit the need for external H₂, as well as other benefits (e.g., the ability to avoid any azeotropes, gasoline cuts, and the like). An oxygenate-based feedstock, including a variety of alcohols and/or other oxygenates, can be used to obtain the Cs+ mixed alcohol composition, which affords the ability to use different front-end techniques for converting the feedstock to the C3+ mixed alcohol composition.

[0050] In some aspects, the front-end process where the feedstock is converted to the Cs+ mixed alcohol composition comprises a ketonization-hydrogenation combination process wherein the feedstock is converted to Cs+ ketone products, which are then hydrogenated to the corresponding Cs+ alcohols. In yet other aspects of the disclosure, the front-end process comprises using a Guerbet-polishing combination process wherein the starting feedstock is converted to an oxygenate composition comprising a mixture of different oxygenate products (e.g., carbonylcontaining compounds and/or alcohols). Any carbonyl-containing compounds included in the oxygenate composition then undergo hydrogenolysis to the 63+ mixed alcohol composition, which can further comprise C4+ alcohols produced from the Guerbet process. Combining these different front-end process techniques with the back-end process according to aspects of the disclosure allows the disclosed method to avoid one or more drawbacks associated with conventional methods, including, for example, avoiding highly endothermic ethanol dehydration, eliminating sensitive Ni-based oligomerizations, and/or avoiding the need for external H₂ addition.

[0051] The disclosed method further provides at least one or more of the following advantages over conventional processes: (1 ) the ability to utilize higher pressures in a diluent-free ketonization reaction, which improves the reaction rate and makes it easier to integrate with downstream processes which are performed under higher pressures; (2) it enables the production of a higher percentage of jet-range products (Cs+) which reduces the burden on downstream coupling processes and as well as reducing the overall carbon loss from CO2, of which the yield is inversely proportional to the average carbon chain length of the ketone; and (3) it reduces the presence of formation of unsaturated byproducts such as aromatic rings due to the increased hydrogenation rates enabled by higher hydrogen partial pressures, resulting in a cleaner product.

Method

[0052] Disclosed herein is a method for converting a C3+ mixed alcohol composition to hydrocarbon fuel products, such as SAF. The method comprises a combination of dehydration, oligomerization, and hydrogenation “back-end” processes to convert the Cs₊ mixed alcohol composition to the hydrocarbon fuel, which facilitates several efficiencies in the overall energy input/output of the method and further avoids certain fallbacks associated with conventional techniques. The back-end processes disclosed herein can be combined with different “front-end” processing techniques that convert oxygenate-based feedstocks to the Cs+ mixed alcohol composition. In some aspects, the back-end processes can be coupled with a ketonization- hydrogenation front-end process that converts an oxygenate-based feedstock to the 63+ mixed alcohol composition using alcohol upgrading to C3+ ketones, which are then hydrogenated to the Cs+ alcohols present in the 63+ mixed alcohol composition. In other aspects, the back-end processes can be coupled with a Guerbet-polishing front-end process that converts an oxygenatebased feedstock to the 63+ mixed alcohol composition using alcohol upgrading to C4+ oxygenates, which are then converted to alcohols present in the C3+ mixed alcohol composition.

[0053] The method disclosed herein comprises a dehydration process wherein a C3+ mixed alcohol composition is exposed to a dehydration catalyst to convert alcohols present in the C3+ mixed alcohol composition to a C3+ mixed olefin composition. The Cs+ olefins can comprise a C3 olefin, a C4 olefin, a C5 olefin, a Ce olefin, a C7 olefin, a Cs olefin, or any combination thereof. In some aspects, the Cs+ mixed olefin composition may comprise a fraction that is made up of Cs+ olefins that can be passed directly to a hydrogenation zone as described herein. In some aspects, the dehydration process can take place in a dehydration zone that comprises the dehydration catalyst. The dehydration catalyst can be selected from solid acid catalysts (e.g., alumina), silicaaluminum oxides (e.g., Sasal Siralox 30 HPV), acidic zeolites (e.g., H-ZSM5), ion exchange resins (e.g., Amberlyst 45 or Amberlyst 70), or combinations thereof. In some particular aspects of the disclosure, the dehydration catalyst is selected to be an acidic silicoaluminate material. In particular aspects, the acidic silicoaluminate material is selected from a silica-alumina oxide available from Sasol (e.g., SIRALOX 30 HPV). The dehydration process can be carried out at pressures ranging from 0 psig to 1000 psig, such as 300 psig to 600 psig, or 400 psig to 550 psig or 450 psig to 550 psig, or 450 psig to 525 psig, or 450 psig to 500 psig. In some aspects, the dehydration process can be carried out at temperatures ranging from 50 °C to 500 °C, such as 100 °C to 500 °C, or 120 °C to 500 °C, or 150 °C to 500 °C, or 200 °C to 500 °C, or 300 °C to 500 °C. In particular aspects, the temperature ranges from 120 °C to 400 °C, such as 200 °C to 350 °C, or 250 °C to 325 °C, or 250 °C to 310 °C, or 260°C to 300 °C, or 275 °C to 300 °C.

[0054] The method also comprises performing an oligomerization process after the dehydration process wherein olefins present in the Cs₊ mixed olefin composition undergo oligomerization to form a Cs+ mixed olefin composition comprising Cs i6+ olefins, such as Cs is. or Cs olefins, or Ca-u olefins. In some aspects, the oligomerization process uses an oligomerization catalyst that comprises a zeolite material. The oligomerization process can be carried out in an oligomerization zone that comprises the oligomerization catalyst. The oligomerization zone can be fluidly coupled with the dehydration zone such that a process stream from the dehydration zone is passed to the oligomerization process stream. In some aspects, Cs+ olefins from the dehydration zone can bypass the oligomerization zone and be passed to a hydrogenation zone as described herein. The oligomerization catalyst can be selected from solid acid catalysts (e.g., alumina), silicaaluminum oxides (e.g., Sasal Siralox 30 HPV), acidic zeolites (e.g., H-ZSM-5, or zeolites sold by Zeolyst including CBV 3014 [Si/AI Ratio 30], CBV 5524 [Si/AI ratio 50], CBV 8014 [Si/AI Ratio 80], and CBV 28014 [Si/AI Ratio 280]), other zeolite catalysts (e.g., BEA or HY), or acidic exchange resins (e.g., Amberlyst 15 or Amberlyst 70). In particular aspects, the oligomerization catalyst can be a zeolite catalyst. In particular aspects, the oligomerization catalyst can be selected from a zeolite sold by Zeolyst (e.g., CBV 3014 [Si/AI Ratio 30], CBV 5524 [Si/AI ratio 50], CBV 8014 [Si/AI Ratio 80], and CBV 28014 [Si/AI Ratio 280]). The oligomerization process can be carried out at pressures ranging from 50 psig to 600 psig, such as 200 psig to 550 psig, or 350 psig to 550 psig, or 400 psig to 550 psig, or 450 psig to 550 psig, or 450 psig to 525 psig, or 450 psig to 500 psig. In particular aspects, the oligomerization process and the dehydration process are carried out at the same pressure or substantially similar pressures (e.g., at pressures that are within ± 1 psig to ± 25 psig of one another). In some aspects, the oligomerization process can be carried out at temperatures ranging from 50 °C to 500 °C, such as 100 °C to 500 °C, or 120 °C to 500 °C, or 150 °C to 500 °C, or 200 °C to 500 °C, or 300 °C to 500 °C. In particular aspects, the temperature ranges from 50 °C to 400 °C, such as 200 °C to 400 °C, or 200 °C to 350 °C, or 250 °C to 300 °C, or 250 °C to 290 °C, or 250 °C to 280 °C, or 250 °C to 270 °C, or 250 °C to 260 °C. In some aspects, the oligomerization process can result in a greater than 60% conversion (single pass) to SAFs. Additionally, the alkenes produced through the oligomerization zone can comprise branching that facilitates lowering the freezing point of any final fuel product to meet jet fuel specifications.

[0055] In some aspects, the Cs+ mixed olefin composition may further comprise a lower olefin portion comprising C3-7 olefins, such as a C3 olefin, a C4 olefin, a C5 olefin, a Ce olefin, and/or a C7 olefin. In some aspects, this lower olefin portion can be recycled back to the start of the oligomerization process, such as by reintroducing an isolated lower olefin portion into the oligomerization zone or reactor by (i) adding the lower olefin portion to the process stream that enters the oligomerization reactor, or (ii) adding the lower olefin portion to any process stream that enters an oligomerization zone of a combined reactor system. In some aspects, recycling can be achieved by adding the lower olefin portion into an inlet of an oligomerization reactor that is separate from any inlet into which a process stream from any dehydration reactor/zone is introduced.

[0056] The method further comprises a hydrogenation process wherein olefins from the oligomerization process are converted to hydrocarbon fuel products, such as SAF. In some aspects, the hydrocarbon fuel products comprise Cs+ alkanes, such as Cs i6+ alkanes, including Cs 16 alkanes or Cs 14 alkanes in particular aspects. In some aspects, the hydrogenation process comprises exposing any Cs+ mixed olefin mixture from the oligomerization zone to a hydrogenation catalyst in the presence of hydrogen. The hydrogenation catalyst can be selected from a metal- mediated support, wherein the metal can be selected from Ni, Pt, Pd, and Ru, and the support can be selected from an oxide support (e.g., alumina), a silica support, or a carbon support. In some additional aspects, a Raney-type catalyst, including Raney Ni, can be used. In some particular aspects, the metal-modified silicoaluminate catalyst comprises nickel on a support, wherein the support is a silicoaluminate material. In particular aspects, the metal-modified silicoaluminate catalyst is a Ni-based silicoaluminate sold by Clariant (e.g., NiSat 310 RS). The hydrogenation process can be carried out in a hydrogenation zone and, in some aspects, the H2 used in the hydrogenation process can be obtained from front-end steps that are performed in aspects of the method to produce the 63+ mixed alcohol composition. The hydrogenation zone is fluidly coupled with the oligomerization and/or dehydration zones. The hydrogenation process can be carried out at pressures ranging from 400 psig to 600 psig, such as 450 psig to 525 psig, or 450 psig to 500 psig. In particular aspects, the hydrogenation process and the dehydration and/or oligomerization processes are carried out at the same pressure or substantially similar pressures (e.g., at pressures that are within ± 1 psig to ± 25 psig of one another). Aspects of the disclosed method can be conducted in a “high-to-low” pressure configuration such that down-stream processes are performed at lower pressures than the pressure used to initiate the process. For example, in some aspects, the hydrogenation process is conducted at pressures that are lower than any other process of the method, including other back-end processes and/or front-end processes described herein. In some aspects, the hydrogenation process can be carried out at temperatures ranging from 50 °C to 500 °C, such as 100 °C to 400 °C, or 150 °C to 400 °C, or 170 °C to 400 °C, or 200 °C to 400 °C, or 300 °C to 400 °C. In particular aspects, the temperature ranges from 50 °C to 400 °C, such as 150 °C to 400 °C, or 200 °C to 350 °C, or 250 °C to 300 °C, or 250 °C to 290 °C, or 250 °C to 280 °C, or 250 °C to 270 °C, or 250 °C to 260 °C, or 150 °C to 300 °C, or 170 °C to 280 °C, or 200 °C to 250 °C. In some aspects, the hydrogenation process can be used to convert any non-dehydrated oxygenates from upstream processes into desired products.

[0057] In some aspects of the disclosure, the different zones of the back-end process can be provided as separate reactors wherein each zone corresponds to a single reactor, such as a dehydration reactor, an oligomerization reactor, a hydrogenation reactor, and the like. In such aspects, the dehydration zone/reactor is in fluid communication with the oligomerization zone/reactor, which in turn is in fluid communication with the hydrogenation zone/reactor. In some other aspects, two or more of the zones of the back-end process can correspond to a single reactor, such as a reactor that houses a combination of two or more of the dehydration zone, the oligomerization zone, and the hydrogenation zone. In aspects where two or more zones are housed within a single reactor, the two or more zones can be in fluid communication with the other zones such that a process stream is allowed to pass through each zone in a sequential fashion. For example, a dehydration zone can be provided in a first section of the reactor (e.g., a dehydration catalyst bed is provided in the first section) and an oligomerization zone can be provided in a second section of the reactor (e.g., an oligomerization catalyst bed is provided in the second section) such that any process flow passes through the dehydration zone first and then to the oligomerization zone. If plural reactors are used (e.g., two zones are contained within one reactor and a third zone is contained within a second reactor), the plural reactors are in fluid communication. The system comprising the dehydration, oligomerization, and hydrogenation zones can be fluidly coupled with one or more optional separation zones, such as separation zones comprising separators configured to separate gases and liquids, separators configured to remove water, and/or separators configured to remove side-products, such as H₂, CO₂, and/or lower alkanes (e.g., C₂₇ alkanes and/or C₂₅ alkanes).

[0058] In some aspects, the method further comprises performing a front-end process to produce the Cs+ mixed alcohol composition. The front-end process is used to convert a starting feedstock to the Cs₊ mixed alcohol composition. In some aspects, the front-end process comprises using either a ketonization-hydrogenation combination process or a Guerbet-polishing combination process. FIGS. 1 A and 1 B show a comparison between the types of representative products obtained using the different front-end processes described in aspects of the present disclosure. [0059] In some aspects, the front-end process is a ketonization-hydrogenation combination process. FIG. 2 provides schematic illustrations of steps used in a method according to aspects of the disclosure where a ketonization-hydrogenation front-end process is combined with the back- end process disclosed herein, with the top schematic showing ketonization and hydrogenation taking place in the same reaction zone and wherein the bottom schematic shows these steps taking place in separate reaction zones. FIG. 3 is a schematic illustration of components (e.g., reactors) and process flow used in a representative method combining a ketonization- hydrogenation combination process and a back-end process according to some aspects of the present disclosure. FIG. 4 provides a schematic illustration of the combined front-end and back- end process using ketonization and hydrogenation and further illustrates exemplary catalysts used and products obtained from some representative aspects of the method.

[0060] In other aspects, the back-end processes can be coupled with a Guerbet-polishing frontend process that converts an oxygenate-based feedstock to the Ca+ mixed alcohol composition using alcohol upgrading to C4+ oxygenates, which are then converted to alcohols present in the Cs+ mixed alcohol composition, particularly C4+ mixed alcohols. FIG. 5 provides a schematic illustration of exemplary steps used in a method according to aspects of the disclosure wherein a Guerbet-polishing front-end process is combined with the back-end process disclosed herein.

[0061 ] In some aspects, the starting feedstock used in the front-end process comprises one or more oxygenates. Oxygenates useful as starting feedstocks in the disclosed method can be obtained from various sources, such as alcohol rich product stream derived from fermentation of biomass or waste resources, such as ethanol produced from corn or sugarcane. Alternatively, mixed oxygenate streams such as acetone-butanol-ethanol (ABE) mixtures can be obtained from ethanol as well. C25 mixed oxygenate streams can also be obtained from the catalytic conversion of syngas. In some aspects, the one or more oxygenates comprise an alcohol, a carbonylcontaining compound, or a combination thereof. In particular aspects, the starting feedstock comprises at least one alcohol comprising at least two carbon atoms (also referred to as a C2+ alcohol). In such aspects, the alcohol is ethanol, ethanol/water mixtures (e.g., 50-50 water-ethanol mixtures), azeotropic ethanol, butanol, or the like. In some representative aspects, the alcohol is ethanol. In yet other aspects, the starting feedstock comprises a carbonyl-containing compound. Exemplary carbonyl-containing compounds include, but are not limited to, ketones, aldehydes, esters, carboxylic acids, and the like. Using the disclosed method, any starting feedstock need not be 100% pure and instead can be of lower purity (e.g., such as 91% ethanol), which allows bypassing energetically expensive techniques used in the art to purify the alcohol prior to any conversions thereof. [0062] In some aspects, the front-end process comprises converting the starting feedstock to the Cs+ mixed alcohol composition using a ketonization-hydrogenation combination process. In the ketonization-hydrogenation combination process, the starting feedstock is exposed to conditions sufficient to promote both the ketonization reaction to form ketones from the feed molecules as well as a cross-aldol condensation reaction to increase the size of the ketones and form a mixed composition ketone composition, such as a C3+ mixed ketone composition. In particular aspects, the C3+ mixed ketone composition comprises C3-18 ketones. In some aspects, the conditions sufficient to promote cross aldol condensation reactions can comprise exposing the starting feedstock to a mixed oxide catalyst comprising a metal promoter. The mixed oxide catalyst can comprise pure zinc oxide, or a mixture of zinc oxide with a secondary metal oxide, such as zirconium oxide, cerium oxide, or another metal oxide capable of promoting ketonization reactions for oxygenates. The molar ratio of zinc oxide to the secondary metal oxide can range from 1 :10 to 10:1. In some aspects, the mixed oxide catalyst comprises a zinc oxide and a zirconium oxide. In some other aspects, the mixed oxide catalyst comprises MgO— AI2O3 or MgO — SiOa. In some aspects the metal promoter is selected from a noble metal, such as Au, Pt, Ru, Rh, Pd, Os, Ir, Cu, Ag, or any combination thereof. In some aspects, the metal promoter is present in an amount ranging from 0.01 wt% to 5 wt%, such as 0.05 wt% to 5 wt%, or 0.1 wt% to 5 wt%, or 0.5 wt% to 5 wt%, or 1 wt% to 5 wt%, or 2 wt% to 5 wt%, or 3 wt% to 5 wt%. In particular aspects, the metal promoter is present in an amount ranging from 0.05 wt% to 3 wt%, such as 0.05 wt% to 1 wt%, or 0.1 wt% to 0.25 wt%, with particular examples using 0.1%. Ketonization and cross aldol condensation also is facilitated by using pressures ranging from ambient pressure to 1500 psig, such as 300 psig to 1200 psig, or 500 psig to 1000 psig; and temperatures ranging from 300 °C to 500 °C, such as 300 °C to 400 °C, or 325 °C to 400 °C, or 350 °C to 400 °C, or 360 °C to 400 °C. In some aspects, the ketonization step can be carried out in a condensation zone. In some particular aspects, the ketonization step can be carried out using conditions and catalysts as described in U.S. Pat. No. 11 ,492,303, the relevant portion of which is incorporated herein by reference.

[0063] The hydrogenation process of the ketonization-hydrogenation combination process comprises exposing the Cs+ mixed ketone composition to a hydrogenation catalyst capable of converting the ketones to alcohols to provide the Cs+ mixed alcohol composition. In some aspects, the hydrogenation catalyst is a metal-promoted oxide catalyst. The metal-promoted oxide catalyst comprises a metal promoter and an oxide. In some aspects, the metal promoter is Ru, Pt, or Pd, and the oxide is TiOp, SiOp, AI2O3, or a combination thereof. In some representative aspects, the hydrogenation catalyst comprises water-tolerant materials and thus facilitates the ability to work under conditions where water amounts might be present that cannot be tolerated in conventional processes. In such representative aspects, the hydrogenation catalyst can be an Ru/TiO2 catalyst, such as a ruthenium on titania extrudate catalyst sold by Degussa (e.g., H7709 X/D 3% Ru). In some aspects, the metal promoter of the hydrogenation catalyst is present in an amount ranging from 0.1 wt% to 10 wt%, such as 0.5 wt% to 6 wt%, or 1 wt% to 3 wt%. In some representative aspects, the metal promoter of the hydrogenation catalyst is present in an amount of 3 wt%. The hydrogenation process can be conducted at pressures ranging from ambient pressure to 1000 psig, such as 300 psig to 1200 psig, or 500 psig to 1000 psig; and temperatures ranging from 100 °C to 250 °C, such as 120 °C to 250 °C, or 150 °C to 250 °C, or 150 °C to 200 °C. In some aspects, the hydrogenation step can be performed in the condensation zone of the ketonization step, or it can be performed in a separate hydrogenation zone.

[0064] In particular aspects, the ketonization-hydrogenation combination process is performed in the same zone, such as in a single reactor. In some such aspects, the ketonization catalyst and the hydrogenation catalyst can be positioned in separate catalyst beds. In some such aspects, the hydrogenation catalyst is positioned downstream of the ketonization catalyst. In yet other aspects, the ketonization catalyst and the hydrogenation catalyst can be positioned in a mixed catalyst bed. In particular aspects, the process stream does not need to be subjected to any separation (e.g., separation to remove water). The ketonization-hydrogenation combination process can produce by-products, some of which can be isolated and diverted to other zones of the overall method. For example, some by-products can include H₂, CO₂, and/or C_{2 5} alkanes. In some aspects, one or more of these by-products can be isolated from the Cs+ mixed alcohol mixture and diverted to a hydrogenation zone of the back-end process described herein. In additional aspects, co-products can be formed during the ketonization-hydrogenation combination process. Such co-products may be useful products that can be isolated and used for other processes. In some aspects, the coproducts comprise acetone, isopropanol, or combinations thereof. In particular aspects, acetone and isopropanol co-products facilitate partially preserving the oxygen originally in the starting feedstock, which can add value to the method. Producing hydrocarbon fuels requires the removal of all oxygen from the feed and since ethanol has a high proportion of oxygen, the theoretical maximum weight yield of fuel from ethanol is thus only 0.616 kg Fuel/ kg EtOH. However, acetone and isopropanol co-products retain the oxygen, which compensates for the loss of carbon through CO₂ during ketonization, and can result in higher weight yields from ethanol converted to fuel.

[0065] In particular aspects using a ketonization-hydrogenation process, a mass yield of jet fuel hydrocarbons (e.g., Cs alkanes) ranging from 40% to 52%, such as 42% to 50%, or 45% to 48% can be obtained from combining the back-end process with the ketonization-hydrogenation process with respect to the starting weight of the starting feedstock. In some representative aspects, the yield was 47%.

[0066] In some aspects of the disclosure, the front-end process can comprise using a Guerbet- polishing combination process to prepare the C3- mixed alcohol composition. The Guerbet- polishing combination process comprises performing a Guerbet process to convert the starting feedstock to an oxygenate composition and a polishing process where carbonyl-containing compounds can be converted to alcohol products. In some aspects, the oxygenate composition can comprise a combination of two or more of C4+ alcohols, 04+ aldehydes, C3+ ketones, and C4+ esters. In particular aspects, the oxygenate composition comprises a mixture of C4+ alcohols, C4+ aldehydes, C3+ ketones, C4+ esters, and C4+ carboxylic acids. In yet other particular aspects, the oxygenate composition comprises a mixture of C4+ alcohols, C3+ ketones, and C4+ esters. In yet other particular aspects, the oxygenate composition comprises a mixture of 04+ alcohols, C4+ aldehydes, and C3+ ketones. In yet other particular aspects, the oxygenate composition comprises a mixture of C4+ alcohols and C3+ ketones. In yet other particular aspects, the oxygenate composition consists essentially of C4+ alcohols. In some aspects, the C4+ alcohols include C4-10 alcohols. In some aspects, the C4+ aldehydes include C4-10 aldehydes. In some aspects, the C3+ ketones include C3-11 ketones. In some aspects, the C4+ esters include C4-12 esters.

[0067] The Guerbet process component of the Guerbet-polishing combination process comprises exposing the starting feedstock to a heterogenous Guerbet catalyst that comprises a metal dispersed on a mixed oxide support. In some aspects, the metal is Cu and the mixed oxide support comprises MgO and AI2O3; however, other metals and supports may be used in certain aspects. For example, Pd can be used instead of Cu and other hydrotalcite-derived supports may be used. In some such aspects, CaO and/or Ga2Os can be used, as can hydroxyapatites. In particular aspects, the Guerbet catalyst is a catalyst as described in U.S. Pat. No. 10,745,330, the relevant portion of which is incorporated herein by reference. In some such aspects, the Guerbet catalyst is a co-precipitated CuO — MgO — AI2O3 catalyst having dispersed and stabilized Cu¹⁺ copper sites at an atomic level (pseudo-single atom) on a MgO — AI2O3 catalyst, wherein the copper percentage ranges from 0.025 wt% to 0.5 wt%, such as 0.05 wt% to 0.25 wt%, or 0.1 wt% to 0.15 wt%. In some representative aspects, the catalyst comprises copper (e.g., Cu¹⁺), which may be a stabilized copper pseudo-single-atom supported on MgO-AhOs support, and wherein the copper is present in an amount ranging from 0.05 wt% to 0.25 wt% based on the total of weight of the catalyst. In some aspects, the reaction is carried out in a single reactor in a condensation zone, which may be the same or different from any condensation reactor used in a ketonization- hydrogenation process.

[0068] The Guerbet process facilitates a condensation reaction that typically produces at least 1 - butanol as a primary product through a hydrogen neutral C-C coupling pathway. In aspects using ethanol as a starting feedstock, the ethanol is dehydrogenated into aldehydes and undergoes base-catalyzed aldol condensation and subsequent hydrogenation to form a fully saturated alcohol product as part of the oxygenate composition. In addition, the oxygenate composition comprises self- and cross-condensation products, including 1 -hexanol and 1 -octanol. And, in some aspects, minor side reactions can occur, thus forming other carbonyl-containing compounds, like esters and ketones. FIG. 6 provides a summary of reaction products that can be produced in a representative Guerbet condensation process used in a Guerbet-polishing combination process.

[0069] One exemplary advantage obtained from the Guerbet condensation component of the Guerbet-polishing combination process is that first converting ethanol to, e.g., C4-8 alcohols offers significant reduction in the dehydration energy requirement compared to straight ethanol dehydration. For example, FIG. 7 compares the expected heat duty required to dehydrate different alcohols to their respective alkenes (normalized by total moles of feed carbon) and illustrates that a multi-fold reduction in energy can be used when dehydrating C4+ alcohols produced from Guerbet condensation, versus directly from ethanol. Without being limited to a single theory, it currently is believed that this difference comes from the fact that 1) C-C coupling during Guerbet condensation also simultaneously removes 1 mol of H₂Oper mol of higher alcohol, and 2) the more substituted secondary alkenes produced from C4+ alcohol dehydration are significantly more stable and thus more thermodynamically favorable. This latter effect can be observed by comparing the dehydration of ethanol and 1 -butanol on acidic alumina catalyst (see FIG. 8), where ethanol requires 60 °C higher temperatures to achieve equivalent conversions. Another advantage of using Guerbet condensation is the ability to leverage the side product pathways to generate in-situ H₂ to remove the need for external H₂ input, specifically through the formation of ketones (e.g., acetone, 2-pentanone). As shown in FIG. 6, formation of ketones is accompanied by the stoichiometric generation of CO₂, while simultaneously producing excess H₂. This chemistry provides a means to fully saturate the final fuel product when starting from an oxygenated feed. In-situ production of H₂ for immediate use in downstream hydrogenation steps (e.g., hydrogenation steps involved in the back-end processes described herein) significantly eliminates complexity associated with generating or sourcing external H₂ (e.g., additional CAPEX, site location, transportation costs).

[0070] Conventional SAF processes require external H₂, which ultimately results in CO2 production as 95% of commercial H₂ is produced through non-renewable steam reforming of natural gas into H₂ and CO₂. This can generate 4 mol of H₂ per mol of CO₂, but accounting for CO₂ emission from combustion and power production, yields a real-world efficiency closer to ~2.4 mol H₂/CO₂. Starting from ethanol, ketone synthesis produces H₂ at 3 H₂/CO₂. Even without accounting for transportation/ delivery, H₂ is produced more efficiently in-situ per CO₂ in the disclosed Guerbet process compared to using external H₂. Ketone side product formation, and therefore the degree of in-situ H₂ formation, can be directly controlled via the loading and dispersion of the metal (e.g., Cu) promoter used for the Guerbet catalyst. Tuning the catalyst composition and synthesis procedure thus allows for control of the excess H₂ output to specifically target the specific amount needed to achieve a completely H₂ neutral overall process. An estimation of the in-situ H2 and CO2 generated as a function of product ketone content is shown in FIG. 9, where the overall process H₂ demand is satisfied at roughly 15-20% ketone production.

[0071 ] While the Guerbet process can be controlled to provide high selectivity to higher alcohols, there is still a portion of the product profile that comprises ketones from in-situ H₂ generation, as well as other oxygenate products, such as carbonyl-containing compounds (e.g., aldehydes, esters, and carboxylic acids). As such, the Guerbet process can be combined with a polishing process to maximize the overall carbon efficiency of the process. In some aspects, the polishing process can be used to hydrogenate certain carbonyl-containing products (e.g., aldehydes, carboxylic acids, and ketones) to their respective alcohols. In additional aspects, any esters formed during the Guerbet process can undergo hydrogenolysis to form their constituent alcohols. As such, the Guerbet-polishing process can provide an alcohol-selective product, including a Cs, mixed alcohol composition used in the back-end process discussed herein. In particular aspects using a hydrogenolysis step, a bimetallic Pd-Re catalyst can be used; however, other suitable catalysts may include an acid catalyst or a metal-promoted catalyst. For example, metal-based catalysts can used in combination with components such as Cr₂O3, ZnO, AI2O3, SiO2, TiO2, ZrO2, zeolites, and carbon. Copper chromite catalysts also can be used. And, the copper can be replaced with metals like Ru, Ag, Pd, and Pt, in some aspects. Subsequent testing has shown that this catalyst performs equivalently on the linear esters (e.g., ethyl acetate, ethyl butyrate) expected to be produced as side products during Guerbet condensation. Hydrogenation of any aldehydes and/or ketones can be carried out with hydrogenation catalysts described herein.

[0072] In particular aspects using a Guerbet-polishing process, a yield of jet fuel hydrocarbons (e.g., Cs 15 alkanes) ranging from 50% to 58%, such as 52% to 57%, or 54% to 56% can be obtained from combining the back-end process with the Guerbet-polishing process. In some representative aspects, the yield was 55%.

[0073] In some aspects, processes used in the front-end and/or back-end processes of the method described herein can produce side-products that can be used to make useful co-products. For example, hydrogenation steps described herein may generate H2 and CO2 side-products that can be used to make useful co-products like methanol and/or methane (FIG. 10). In certain aspects, reactions with H₂ and CO2 to produce methane and/or methanol can partially recapture amounts of H2 and CO2 produced in a hydrogenation process (e.g., such as in a front-end and/or back-end process). In some aspects, H2:CO2 ratios vary from -2.2-2.7 based on average ketone carbon number in the hydrogenation process. Forming methanol can use lower H2:CO2 ratios, whereas methane production typically requires more H2. Overview of Several Aspects

[0074] Aspect 1 . Disclosed herein, along with additional aspects as described in the present disclosure, is a method for forming a hydrocarbon fuel product, comprising: forming a Cs+ mixed alcohol composition from a feedstock; exposing the Cs+ mixed alcohol composition to an acidic silicoaluminate catalyst in a dehydration zone operated at a pressure ranging from 400 psig to 550 psig and a temperature ranging from 200 °C to 400 °C to provide a C3+ mixed olefin composition; exposing the Cs+ mixed olefin composition to a zeolite material in an oligomerization zone operated at a pressure ranging from 400 psig to 550 psig and a temperature ranging from 200 °C to 350 °C to provide a Cs+ mixed olefin composition; and exposing the Cs+ mixed olefin composition to a metal-modified silicoaluminate catalyst in the presence of hydrogen in a hydrogenation zone to provide the hydrocarbon fuel product.

[0075] Aspect 2. With respect to Aspect 1 , the Ca+ mixed alcohol composition comprises a C3 alcohol, a C4 alcohol, a C₅ alcohol, a Ce alcohol, a C? alcohol, a Cs alcohol, or any combination thereof; the C3+ mixed olefin composition comprises a C3 olefin, a C4 olefin, a C5 olefin, a Ce olefin, a C7 olefin, a Cs olefin, or any combination thereof; and/or the Cs+ mixed olefin composition comprises a Cs olefin, a C9 olefin, a C10 olefin, a Cn olefin, a C12 olefin, a C13 olefin, a C14 olefin, a C15 olefin, a C16 olefin, a C17 olefin, a Cis olefin, or any combination thereof.

[0076] Aspect 3. With respect to Aspect 2, the Cs+ mixed olefin composition further comprises a lower olefin portion comprising a C3 olefin, a C4 olefin, a C₅ olefin, a Ce olefin, and/or a C₇ olefin and wherein the lower olefin portion is recycled back to the oligomerization zone.

[0077] Aspect 4. With respect to any or all of Aspects 1 -3, the dehydration zone, the oligomerization zone, and the hydrogenation zone are each independently operated at pressures that range from 450 psig to 500 psig and wherein the oligomerization zone and/or the hydrogenation zone are further operated at a pressure that is the same as, or that is within ± 1 psig to ± 25 psig of, a pressure at which the dehydration zone is operated.

[0078] Aspect 5. With respect to any or all of Aspects 1 -4, the hydrogenation zone is operated at a pressure that is lower than a pressure at which each of the dehydration zone and the oligomerization zone are operated.

[0079] Aspect 6. With respect to any or all of Aspects 1 -5, the feedstock comprises an oxygenate material selected from a C24 alcohol, a carbonyl-containing compound, or a combination thereof.

[0080] Aspect 7. With respect to Aspect 6, the following can apply: (i) the C2-4 alcohol is ethanol; and/or (ii) the carbonyl-containing compound is a ketone, an aldehyde, an ester, a carboxylic acid or a combination thereof. [0081 ] Aspect 8. With respect to any or all of Aspects 1 -7, the feedstock comprises a C2 -4 alcohol and the method further comprises exposing the C24 alcohol to a mixed oxide catalyst in a condensation zone to produce a C3+ mixed ketone composition, wherein the mixed oxide catalyst comprises a metal promoter selected from Au, Cu, Ag, Pt, Ru, Rh, Pd, Os, Ir, or any combination thereof.

[0082] Aspect 9. With respect to Aspect 8, the method further comprises exposing the Cs₊ mixed ketone composition to a hydrogenation catalyst to provide the Ca+ mixed alcohol composition, wherein the hydrogenation catalyst is present in the condensation zone or is present in a separate hydrogenation zone.

[0083] Aspect 10. With respect to Aspects 9 or 10, the hydrogenation catalyst comprises a metal-promoted oxide catalyst comprising an oxide and a metal promoter selected from Ru, Pt, or Pd.

[0084] Aspect 11. With respect to any or all of Aspects 8-10, acetone, isopropanol, or a combination thereof is isolated from the condensation zone.

[0085] Aspect 12. With respect to any or all of Aspects 8-11 , the hydrocarbon fuel comprises Cs+ alkane compounds and is obtained in a yield ranging from at least 40%, relative to the starting feedstock.

[0086] Aspect 13. With respect to any or all of Aspects 1-12, the method is free of, or does not include, a purification and/or separation step wherein water is removed from a process stream of the method.

[0087] Aspect 14. With respect to any or all of Aspects 1-7, and/or 13, the feedstock comprises a C24 alcohol and the method further comprises exposing the C2-4 alcohol to a heterogeneous Guerbet catalyst in a condensation zone to produce an oxygenate composition comprising 1 - butanol, wherein the heterogeneous Guerbet catalyst comprises a metal dispersed on a mixed oxide support.

[0088] Aspect 15. With respect to Aspect 14, the oxygenate composition provides the C3+ mixed alcohol composition.

[0089] Aspect 16. With respect to Aspects 14 and/or 15, the heterogeneous Guerbet catalyst comprises Cu supported on an MgO-AI₂O3 support, wherein the Cu is present in an amount ranging from 0.05 wt% to 0.25 wt%.

[0090] Aspect 17. With respect to any or all of Aspects 14-16, the oxygenate composition further comprises C4-10 aldehydes, C3-11 ketones, C4-12 esters, or any combination thereof and the method further comprises exposing the oxygenate composition to a bimetallic catalyst to promote hydrogenation of any C4-10 aldehydes, C3-11 ketones, and/or hydrogenolysis of any C4-12 esters present in the oxygenate composition to produce the of C3+ mixed alcohol composition.

[0091 ] Aspect 18. With respect to any or all of Aspects 14-17, the bimetallic catalyst comprises a Pd-Re alloy on a carbon support.

[0092] Aspect 19. In any or all aspects of the present disclosure, the method can be a method for forming a hydrocarbon fuel product, comprising: exposing a C24 alcohol to a mixed oxide catalyst in a condensation zone to produce a Cs+ mixed ketone composition, wherein the mixed oxide catalyst comprises a metal promoter selected from Au, Cu, Ag, Pt, Ru, Rh, Pd, Os, Ir, or any combination thereof; exposing the C3+ mixed ketone composition to a hydrogenation catalyst to provide a 63+ mixed alcohol composition, wherein the hydrogenation catalyst is present in the condensation zone or is present in a separate hydrogenation zone; exposing the C3+ mixed alcohol composition to a dehydration catalyst in a dehydration zone operated at a pressure ranging from 0 psig to 1000 psig and a temperature ranging from 50 °C to 500 °C to provide a C3+ mixed olefin composition; exposing the C3+ mixed olefin composition to an oligomerization catalyst in an oligomerization zone operated at a pressure ranging from 0 psig to 1000 psig and a temperature ranging from 50 °C to 400 °C to provide a Cs+ mixed olefin composition; and exposing the Cs+ mixed olefin composition to a hydrogenation catalyst in the presence of hydrogen in a hydrogenation zone to provide the hydrocarbon fuel product.

[0093] Aspect 20. With respect to Aspect 19, the dehydration catalyst comprises an acidic silicoaluminate catalyst, the oligomerization catalyst comprises a zeolite material, and the hydrogenation catalyst comprises a metal-modified silicoaluminate catalyst.

[0094] Aspect 21 . In any or all aspects of the disclosure, the method can be a method for forming a hydrocarbon fuel product, comprising: exposing a C2-4 alcohol to a heterogeneous Guerbet catalyst in a condensation zone to produce an oxygenate composition comprising 1 - butanol, wherein the heterogeneous Guerbet catalyst comprises a metal dispersed on a mixed oxide support; exposing the oxygenate composition to dehydration catalyst in a dehydration zone operated at a pressure ranging from 0 psig to 1000 psig and a temperature ranging from 50 °C to 500 °C to provide a C3+ mixed olefin composition; exposing the Cs+ mixed olefin composition to an oligomerization catalyst in an oligomerization zone operated at a pressure ranging from 0 psig to 1000 psig and a temperature ranging from 50 °C to 400 °C to provide a Cs+ mixed olefin composition; and exposing the Cs+ mixed olefin composition to a hydrogenation catalyst in the presence of hydrogen in a hydrogenation zone to provide the hydrocarbon fuel product. [0095] Aspect 22. With respect to Aspect 21 , the dehydration catalyst comprises an acidic silicoaluminate catalyst, the oligomerization catalyst comprises a zeolite material, and the hydrogenation catalyst comprises a metal-modified silicoaluminate catalyst.

[0096] Aspect 23. With respect to Aspect 21 and/or 22, the oxygenate composition further comprises C4 -10 aldehydes, C3-11 ketones, C4-12 esters, or any combination thereof and the method further comprises exposing the oxygenate composition to a catalyst to promote hydrogenation of any C4-10 aldehydes, C3-1 1 ketones, and/or to promote hydrogenolysis of any C4-12 esters present in the oxygenate composition, wherein the oxygenate composition is exposed to the catalyst to promote hydrogenation prior to exposing the oxygenate composition to the dehydration catalyst.

[0097] Examples

Example 1

[0098] In this example, a ketonization process component of a ketonization-hydrogenation frontend process was evaluated. For ketonization, the following catalyst and conditions were utilized (results shown in FIGS. 11 A and 11 B): The reaction was conducted in a downflow plug flow reactor over a 0.25 wt% Pd on ZnO-ZrO2 catalyst (Zn:Zr ratio = 1 :2). 91 wt% ethanol & 9 wt% H₂O was used as the reaction feed, with no diluent gas. The catalyst bed temperature was 383 °C and the weight hourly space velocity was 0.75 hr ¹ with respect to the ethanol. System pressure was varied from 0 to 500 psig.

[0099] As can be seen in FIG. 11 A, the ketonization process could be carried out at a high pressure (e.g., 500 psig) without using a diluent (such as an inert gas like N₂). FIG. 11 B also shows that the high pressure used in the ketonization process facilitated a higher yield of jet-range products compared to lower pressures performed with a diluent. As shown in FIG. 11 B, a cleaner product was obtained without needing to use a diluent. Results also are summarized in Table 1 , below. This example therefore shows that the disclosed method can achieve benefits discussed in the present disclosure.

[0100] Additional results obtained according to the following reaction parameters are summarized in Table 2: The reactions were conducted in a downflow plug reactor over a 0.1 wt% Pd on ZnO- ZrOa catalyst (Zn:Zr ratio = 1 :2). 91 wt% ethanol & 9 wt% H2O was used as the reaction feed, with no diluent gas. The catalyst bed temperature was 383 °C and the weight hourly space velocity was 0.75 hr¹ with respect to the feed ethanol. The system pressure was varied from 500-1500 psig. The results show the general trend of increasing ketone chain length and the pressure.

[0101] For results shown in FIG. 12A (and summarized in Table 3, below): The reactions were conducted in a downflow plug reactor over a 0.1% Pd on ZnO-ZrC>2 catalyst (Zn:Zr ratio = 1 :2). 91 wt% ethanol & 9 wt% H₂Owas used as the reaction feed, with no diluent gas. FIG. 12A shows that high conversion rates of ethanol can be maintained at a wide range of WHSV (hr¹) from 0.84- 2.37 hr ¹ by increasing the temperature of the reaction from 378 °C to 393 °C to compensate for the decrease in activity, with the tradeoff being the reduction of the average carbon length of the ketone product as evident in the ketone distribution by carbon number (Table 3).

[0102] FIG. 12 B shows that the catalyst was stable and active over long TOS times (over 800 hours) with less than 2% decrease in ethanol conversion over that time frame. The reaction was conducted in a downflow plug reactor over a 0.1 wt% Pd on ZnO-ZrOs catalyst (Zn:Zr ratio = 1 :2).

91 wt% ethanol & 9 wt% H₂O was used as the reaction feed, with no diluent gas. The catalyst bed temperature was 383 °C and the weight hourly space velocity was 0.75 hr ¹. The system pressure was maintained at 550 psig. Results also are summarized in Table 4, below.

Example 2

[0103] In this example, a hydrogenation process component of a ketonization-hydrogenation front-end process was evaluated. For hydrogenation, the product from Example 1 was exposed to the following catalyst and conditions: The reaction was conducted in a downflow plug flow reactor over a titania (P25 Titania or 7711 Titania from Degussa) catalyst with a Ru loading of 3 wt%. The condensed liquid phase product from Example 1 was used as the primary feedstock. Pure H2 as used as the carrier gas, which was fed in a weight ratio of H2 to organic molecules of 0.058. This ratio corresponds the expected in-situ production of H2 during ketonization. The catalyst bed temperature was 250 °C, the overall system pressure was maintained at 600 psi, and weight hourly space velocity was varied between 0.5 and 12 hr¹.

[0104] FIGS. 13A and 13B show conversion rates obtained from the hydrogenation process using different WHSV (hr¹) (FIG. 13A) and time on stream (TOS) (FIG. 13B) parameters. It was determined that >98% of the ketones from the ketonization step were converted to corresponding alcohols, even at high WHSV. FIG. 13B shows that the catalyst was stable and active over long TOS times (over >700 hours). Results for FIG. 13A also are summarized in Table 5; results for FIG. 13B are summarized in Table 6.

Example 3

[0105] In this example, a dehydration step of a representative back-end process was evaluated using the Cs+ mixed alcohol composition from Example 2. For dehydration, the following catalyst and conditions were utilized: the reaction was conducted in a downflow plug flow reactor over a mixed oxide catalyst (silica-alumina oxide SIRAL HPV 40 from Sasol). The mixed Cs+ alcohols produced from Example 2 was used as the primary feedstock. The catalyst bed temperature was 250 °C, an overall system pressure of 550 psig, and a weight hourly space velocity of 0.5 hr ¹ (FIG. 14B) or in a range from 1 .5 to 12 hr ¹ (FIG. 14A)

[0106] FIGS. 14A and 14B show overall alcohol conversion rates obtained from the dehydration process using different WHSV (hr¹) (FIG. 14A) and time on stream (TOS) (FIG. 14B) parameters. It was determined that >99% of the alcohols from Cs+ mixed alcohol composition were converted to corresponding alkenes, even at high WHSV. FIG. 14B shows that the catalyst was stable and active over long TOS times (over >500 hours). Results for FIG. 14A also are summarized in Table 7; results for FIG. 14B are summarized in Table 8.

[0107] Additional reactions were conducted to evaluate other appropriate catalyst and conditions. In one example, the reaction was conducted in a downflow plug flow reactor over an acidic aluminosilicate catalyst (Sasol SIRAL 40 HPV). 2-Pentanol was used as the primary feedstock with a feed rate of 0.1 mL/min, with N2 as the carrier gas with a feed rate of 10 sccm/min. The catalyst bed temperature was 250 °C, the overall system pressure was varied from 50 psig to 525 psig, and weight hourly space velocity was 0.48 hr ¹ with respect to 2-pentanol. Conversion of 2- pentanol to the respective pentene was observed to be near complete for all tested pressure conditions. Results are summarized in Table 9.

[0108] Additional catalysts were tested for their dehydration efficacy on mixed Cs+ alcohol streams. In such examples, the reaction was conducted in a downflow plug flow reactor over an acidic resin-based catalyst (Amberlyst 45). Organic stream of mixed Cs+ alcohols produced from Example 2 was used as the primary feedstock with a feed rate of 0.05 mL/min, with N₂ as the carrier gas with a feed rate of 5 sccm/min. The catalyst bed temperature was 158 °C, weight hourly space velocity was 0.48 (g feed alcohols/ g Amberlyst 45 catalyst (dry basis) * hr), and an overall system pressure from 300 to 550 psig. Among the alcohol species present in the feed, isopropanol is the most difficult to dehydrate, while C4+ alcohols are more readily converted to alkenes. The results of the reaction are therefore divided into these respective categories, and presented in Table 10, which shows that dehydration is relatively insensitive to system pressure on Amberlyst 45.

[0109] In other examples, the reaction was conducted in a downflow plug flow reactor over a mixed oxide catalyst (silica-alumina oxide SIRAL HPV 40 from Sasol or alumina from Clariant). The organic phase containing mixed Cs+ alcohols produced from Example 2 was used as the primary feedstock while the aqueous phase produced from Example 2 was used as the cofeed, in order to better represent realistic flow conditions. The organic and aqueous phase was cofed in a weight ratio of 2.4:1 , respectively. The catalyst bed temperature was 250 °C, the overall system pressure was 550 psig, and the weight hourly space velocity was varied from 0.75-12 hr ¹ with respect to the organic phase. The results of the reaction are therefore divided into these respective categories, and presented in Table 11 , which shows SIRAL exhibits a higher performance compared to alumina, particularly in terms of isopropanol conversion.

[0110] In yet other examples, the reaction was conducted in a downflow plug flow reactor over a mixed oxide catalyst (silica-alumina oxide SIRAL HPV 40 from Sasol). The organic phase containing mixed Ca+ alcohols produced from Example 2 was used as the primary feedstock while the aqueous phase produced from Example 2 was used as the cofeed. The organic and aqueous phase was cofed in a weight ratio of 2.4:1 , respectively. The catalyst bed temperature was 300 °C, the overall system pressure was 550 psig, and the weight hourly space velocity was varied from 0.75-12 hr ¹ with respect to the organic phase. The results in Table 12 show significant improvement of isopropanol conversion achieved at 300 °C compared to 250 °C.

[0111] Additionally, FIGS. 14C and 14D show a comparison of dehydration duty (FIG. 14C) and dehydration temperature (FIG. 14D) for a conventional ethylene-based pathway for producing SAF as compared with the disclosed method. A lower overall duty for dehydration using the disclosed method was observed in comparison with result from an ethylene-based process, likely due to the larger alcohols and/or secondary alcohols included in the Cs+ mixed alcohol composition (FIG. 14C). Additionally, lower temperatures could be used to convert the types of alcohols included in the C3+ mixed alcohol composition in comparison to alcohols with carbon numbers below C3, such as in ethanol, thus showing that the dehydration component of the back-end process can help avoid coking. Results for FIG. 14C also are summarized in Table 13; results for FIG. 14D are summarized in Table 14.

Example 4

[0112] In this example, an oligomerization step of a representative back-end process was evaluated using the alkene mixture obtained from Example 3, the composition of which is provided in first column of Table 15. For oligomerization, the following catalyst and conditions were utilized: The reaction was conducted in a downflow plug flow reactor over an acidic zeolite based catalyst (Zeolyst CBV8014). No carrier gas was used. The feed was the alkene mixture obtained from Example 3, after the aqueous phase generated from dehydration was removed. For FIGS. 15A and 15B, the catalyst bed temperature was 300 °C, the overall system pressure was 400 psig, and the weight hourly space velocity was 0.75 hr ¹ with respect to the feed alkenes. Additional examples with variations in catalyst, WHSV, pressure, and temperature are presented in Table 15. Table 15 shows the effects of varying catalyst and operating conditions on the oligomerization product profile.

[0113] FIG. 15A shows conversion rates obtained from the oligomerization process using different time on stream (TOS) parameters. It was determined that a >60% yield of jet-range olefins could be obtained after a single pass with over 200 hours TOS. FIG. 15B shows yields of the various carbon products obtained, with C7 or lower alkenes being eligible for recycling through the oligomerization step to improve jet range yields. Results for FIG. 15A also are summarized in Table 16; results for FIG. 15B are summarized in Table 17.

Example 5

[0114] In this example, a hydrogenation step of a representative back-end process was evaluated using the Cs+ mixed olefin composition obtained from Example 4. For hydrogenation of the Cs+ mixed olefin composition to saturated products, the following catalyst and conditions were utilized: The reaction was conducted using 2 wt% Pt on carbon catalyst. The oligomerized alkene product from Example 4 was directly used as the feedstock for this process, with a liquid feed rate of 0.1 mL/min. Pure hydrogen gas was cofed at a rate of 40 mUmin H₂. The catalyst bed temperature was 300 °C, with a system pressure of 300 psig, and a weight hourly space velocity of 1 hr¹ with respect to the alkene feed. Greater than 99.5% conversion of alkenes to their respective alkanes was achieved during the reaction. Following the reaction, the product was distilled between 155 °C to 245 °C to produce a cut appropriate for jet fuel.

[0115] FIG. 16 shows the distribution and composition of the hydrocarbons in the jet range distillation cut obtained from the hydrogenation process. FIG. 17 provides a graph showing that the SAF product obtained from the hydrogenation process meets Tier a & p specifications.

Example 6

[0116] In this example, Guerbet condensation was evaluated as a process component of a frontend process according to aspects of the present disclosure. The reaction was conducted in a downflow plug flow reactor using a MgO-AI₂C>3 hydrotalcite-derived mixed oxide catalyst (Mg:AI molar ratio = 4:1) with a Cu loading of 0.1 wt%. Pure ethanol was used as the primary feedstock, with hydrogen as the carrier gas, fed in a molar ratio of 1 :5 for ethanol/H₂. The catalyst bed temperature was 325 °C, the overall system pressure was maintained at 600 psi, and weight hourly space velocity was 0.15 hr¹. As can be seen in FIG. 18, high conversion rates and alcohol selectivities were observed. Results also are summarized in Table 18, below.

Example 7

[0117] In this example, ethyl acetate is converted to alcohol using hydrogenolysis to establish the ability of using a polishing step to convert carbonyl-containing products produced in a Guerbet process to alcohols. The reaction was conducted in a downflow plug flow reactor using 3 wt% Pd & 6 wt% Re loaded on Hyperion 07C carbon catalyst. Pure ethyl acetate was cofed with hydrogen gas in a 1 :35 molar ratio. The catalyst bed temperature was 200 °C, the overall system pressure was maintained at 600 psi, and weight hourly space velocity was 0.27 hr- 1 with respect to ethyl acetate. FIG. 19 shows the results from the stable hydrogenolysis over 130 hours, with over 90% yield to the target products and >97% conversion. Using this method for polishing products produced during a Guerbet process used for front-end conversion to a C3+ mixed alcohol composition, the overall carbon efficiency can be boosted from -80% to above 92%, significantly improving the commercial viability of converting starting feedstocks to SAF products using a method according to aspects of the method disclosed herein.

[0118] FIG. 20 shows a gas chromatogram of jet-range alkene products produced from oligomerizing a 63+ mixed alcohol composition (specifically a 04+ mixed alcohol composition) obtained from a front-end process using Guerbet condensation and a polishing process.

Example 8

[0119] In this example, mixed alcohols generated by the upstream Guerbet process were converted to jet fuel via the downstream process. The dehydration and oligomerization reactions were conducted in an integrated two stage setup (dehydration followed by oligomerization) comprising two downflow plug flow reactors arranged in sequence (first dehydration followed by oligomerization), with a cooled separation trap in between the two reactors that condenses and separates out the aqueous phase produced from dehydration while passing on the vapor phase alkene products to the subsequent oligomerization reactor. The dehydration reactor used an alumina catalyst (BASF-A-0104), while the oligomerization reactor used a zeolite catalyst (Zeolyst CBV8014 or Beta zeolite - CP811 C-300). The dehydration reaction was conducted at 370 °C, the oligomerization reaction was conducted at 200 °C, and the separation trap was kept at 2 °C. The feedstock was an alcohol mixture derived from the upstream process comprising C4 to Cs alcohols with the composition listed in Table 19, and fed into the reactor at a rate of 0.01 mL/min. Nitrogen gas was cofed at a rate of 45 sccm/min. The weight hourly space velocity was 0.312 hr¹ for the dehydration reaction and 0.2 hr¹ for the oligomerization reaction, both with respect to the initial feed.

[0120] The mixed alkene product from the oligomerization reaction was subsequently used as the feed for a hydrogenation reaction, which was conducted in a downflow plug flow reactor using a Ni-AhOs hydrogenation catalysts. The alkenes were fed at a rate of 0.1 mL/min along with a hydrogen stream cofed at a rate of 40 sccm/min. The catalyst bed temperature was 300 °C, the overall system pressure was 500 psig, and the weight hourly space velocity was 0.2 hr¹. Greater than 99.5% conversion of alkenes to alkanes was achieved during the reaction. The final alkane mixture was distilled between 155 °C to 245 °C to produce a cut appropriate for jet fuel. Examples of distillation results (recovered mass across a range of distillation temperatures) of these fuels are presented in Table 20, showing that oligomerization performed at two different temperatures (200°C and 250°C) and with two different catalysts all produced a fuel profile similar to the jet fuel standard.

Example 9

[0121 ] In this example, the ability to prepare co-products using CO2 and H2 produced in the disclosed method was evaluated. In particular, methane and methanol were produced by combining CO2 and H2 produced during a hydrogenation process of a back-end portion of the disclosed method. Theoretical methane and methanol yields are summarized in FIG. 21 A. FIG.

21 B shows theoretical results of measured carbon loss as CO2 for a method where no co-products are formed as compared to when methane and/or methanol are produced.

[0122] In view of the many possible embodiments to which the principles of the present disclosure may be applied, it should be recognized that the illustrated embodiments are only preferred examples of the present disclosure and should not be taken as limiting the scope of the disclosure. Rather, the scope is defined by the following claims. We therefore claim as our invention all that comes within the scope and spirit of these claims.

Claims

We claim:

1 . A method for forming a hydrocarbon fuel product, comprising: forming a Cs+ mixed alcohol composition from a feedstock; exposing the Cs+ mixed alcohol composition to an acidic silicoaluminate catalyst in a dehydration zone operated at a pressure ranging from 400 psig to 550 psig and a temperature ranging from 200 °C to 400 °C to provide a Cs+ mixed olefin composition; exposing the Cs+ mixed olefin composition to a zeolite material in an oligomerization zone operated at a pressure ranging from 400 psig to 550 psig and a temperature ranging from 200 °C to 350 °C to provide a Cs+ mixed olefin composition; and exposing the Ca₊ mixed olefin composition to a metal-modified silicoaluminate catalyst in the presence of hydrogen in a hydrogenation zone to provide the hydrocarbon fuel product.

2. The method of claim 1 , wherein the C3+ mixed alcohol composition comprises a C3 alcohol, a C4 alcohol, a C5 alcohol, a Ce alcohol, a C7 alcohol, a Cs alcohol, or any combination thereof; the Cs+ mixed olefin composition comprises a C3 olefin, a C4 olefin, a C₅ olefin, a C& olefin, a C7 olefin, a Cs olefin, or any combination thereof; and/or the Ca+ mixed olefin composition comprises a Cs olefin, a Cg olefin, a C10 olefin, a Cn olefin, a C12 olefin, a C13 olefin, a C14 olefin, a C15 olefin, a Cis olefin, a C17 olefin, a Cis olefin, or any combination thereof.

3. The method of claim 2, wherein the Cs+ mixed olefin composition further comprises a lower olefin portion comprising a C3 olefin, a C4 olefin, a C5 olefin, a Ce olefin, and/or a C7 olefin and wherein the lower olefin portion is recycled back to the oligomerization zone.

4. The method of claim 1 , wherein the dehydration zone, the oligomerization zone, and the hydrogenation zone are each independently operated at pressures that range from 450 psig to 500 psig and wherein the oligomerization zone and/or the hydrogenation zone are further operated at a pressure that is the same as, or that is within ± 1 psig to ± 25 psig of, a pressure at which the dehydration zone is operated.

5. The method of claim 1 , wherein the hydrogenation zone is operated at a pressure that is lower than a pressure at which each of the dehydration zone and the oligomerization zone are operated.

6. The method of claim 1 , wherein the feedstock comprises an oxygenate material selected from a C2-4 alcohol, a carbonyl-containing compound, or a combination thereof.

7. The method of claim 6, wherein (i) the C24 alcohol is ethanol; and/or (ii) the carbonyl-containing compound is a ketone, an aldehyde, an ester, a carboxylic acid or a combination thereof.

8. The method of claim 1 , wherein the feedstock comprises a C2-4 alcohol and the method further comprises exposing the C2-4 alcohol to a mixed oxide catalyst in a condensation zone to produce a C3+ mixed ketone composition, wherein the mixed oxide catalyst comprises a metal promoter selected from Au, Cu, Ag, Pt, Ru, Rh, Pd, Os, Ir, or any combination thereof.

9. The method of claim 8, wherein the method further comprises exposing the C3+ mixed ketone composition to a hydrogenation catalyst to provide the Cs+ mixed alcohol composition, wherein the hydrogenation catalyst is present in the condensation zone or is present in a separate hydrogenation zone.

10. The method of claim 9, wherein the hydrogenation catalyst comprises a metal- promoted oxide catalyst comprising an oxide and a metal promoter selected from Ru, Pt, or Pd.

11 . The method of claim 8, wherein acetone, isopropanol, or a combination thereof is isolated from the condensation zone.

12. The method of claim 8, wherein the hydrocarbon fuel comprises Ca+ alkane compounds and is obtained in a yield of at least 40%, relative to the starting feedstock.

13. The method of claim 8 wherein the method is free of, or does not include, a purification and/or separation step wherein water is removed from a process stream of the method.

14. The method of claim 1 , wherein the feedstock comprises a C2-4 alcohol and the method further comprises exposing the C2-4 alcohol to a heterogeneous Guerbet catalyst in a condensation zone to produce an oxygenate composition comprising 1 -butanol, wherein the heterogeneous Guerbet catalyst comprises a metal dispersed on a mixed oxide support.

15. The method of claim 14, wherein the oxygenate composition provides the C3+ mixed alcohol composition.

16. The method of claim 14, wherein the heterogeneous Guerbet catalyst comprises Cu supported on an MgO-AhOs support, wherein the Cu is present in an amount ranging from 0.05 wt% to 0.25 wt%.

17. The method of claim 14, wherein the oxygenate composition further comprises C4-10 aldehydes, C3-11 ketones, C4-12 esters, or any combination thereof and the method further comprises exposing the oxygenate composition to a bimetallic catalyst to promote hydrogenation of any C4-10 aldehydes, C3-11 ketones, and/or hydrogenolysis of any C4-12 esters present in the oxygenate composition to produce the of C3+ mixed alcohol composition.

18. The method of claim 17, wherein the bimetallic catalyst comprises a Pd-Re alloy on a carbon support.

19. A method for forming a hydrocarbon fuel product, comprising: exposing a C24 alcohol to a mixed oxide catalyst in a condensation zone to produce a Cs₊ mixed ketone composition, wherein the mixed oxide catalyst comprises a metal promoter selected from Au, Cu, Ag, Pt, Ru, Rh, Pd, Os, Ir, or any combination thereof; exposing the Cs₊ mixed ketone composition to a hydrogenation catalyst to provide a Cs₊ mixed alcohol composition, wherein the hydrogenation catalyst is present in the condensation zone or is present in a separate hydrogenation zone; exposing the Cs+ mixed alcohol composition to a dehydration catalyst in a dehydration zone operated at a pressure ranging from 0 psig to 1000 psig and a temperature ranging from 50 °C to 500 °C to provide a C3+ mixed olefin composition; exposing the Cs+ mixed olefin composition to an oligomerization catalyst in an oligomerization zone operated at a pressure ranging from 0 psig to 1000 psig and a temperature ranging from 50 °C to 400 °C to provide a Cs+ mixed olefin composition; and exposing the Cs+ mixed olefin composition to a hydrogenation catalyst in the presence of hydrogen in a hydrogenation zone to provide the hydrocarbon fuel product.

20. The method of claim 19, wherein the dehydration catalyst comprises an acidic silicoaluminate catalyst, the oligomerization catalyst comprises a zeolite material, and the hydrogenation catalyst comprises a metal-modified silicoaluminate catalyst.

21 . A method for forming a hydrocarbon fuel product, comprising: exposing a C24 alcohol to a heterogeneous Guerbet catalyst in a condensation zone to produce an oxygenate composition comprising 1 -butanol, wherein the heterogeneous Guerbet catalyst comprises a metal dispersed on a mixed oxide support; exposing the oxygenate composition to dehydration catalyst in a dehydration zone operated at a pressure ranging from 0 psig to 1000 psig and a temperature ranging from 50 °C to 500 °C to provide a C3+ mixed olefin composition; exposing the C3+ mixed olefin composition to an oligomerization catalyst in an oligomerization zone operated at a pressure ranging from 0 psig to 1000 psig and a temperature ranging from 50 °C to 400 °C to provide a Cs+ mixed olefin composition; and exposing the Cs+ mixed olefin composition to a hydrogenation catalyst in the presence of hydrogen in a hydrogenation zone to provide the hydrocarbon fuel product.

22. The method of claim 21 , wherein the dehydration catalyst comprises an acidic silicoaluminate catalyst, the oligomerization catalyst comprises a zeolite material, and the hydrogenation catalyst comprises a metal-modified silicoaluminate catalyst.

23. The method of claim 21 , wherein the oxygenate composition further comprises C4-10 aldehydes, C3-11 ketones, C4-12 esters, or any combination thereof and the method further comprises exposing the oxygenate composition to a catalyst to promote hydrogenation of any C4 -10 aldehydes, C3-11 ketones, and/or to promote hydrogenolysis of any C412 esters present in the oxygenate composition, wherein the oxygenate composition is exposed to the catalyst to promote hydrogenation prior to exposing the oxygenate composition to the dehydration catalyst.